1. Field
Embodiments of the present disclosure pertain to imaging technologies and, in particular, to high resolution magnetic force microscopy.
2. Description of the Related Art
As technologies increasingly operate at nanoscale dimensions, the significance of high resolution microscopy has increased. Scanning probe microscopy (SPM) is recognized as an important technique for surface measurements at high resolution (e.g., nanoscale accuracy).
Magnetic force microscopy (MFM) is a mode of SPM that has been developed to measure the magnetic properties of a sample. In MFM, a separation distance of about 15-20 nm is maintained between a probe tip and a sample, which each comprise magnetic materials. By scanning the MFM probe tip over the sample surface, long-range magnetic interactions between the tip and surface may be measured.
Today, the span of MFM applications is truly diverse. Applications may include, but are not limited to, analysis of secret information by the FBI, magnetization distribution in systems such as recording media, magnetostatic bacteria, and other systems containing magnetic materials. In particular, MFM is extensively used in the data storage industry to measure magnetization distributions in recording media and heads and, therefore, is instrumental in devising new ways to add more data into a recording systems.
However, the spatial resolution of conventional MFM under ambient conditions, on the order of 20-25 nm in air, is an order of magnitude worse than the resolution of atomic force microscopy (AFM), about 2-3 nm, and roughly two orders of magnitude worse than the resolution of scanning tunneling microscopy (STM), which has a resolution on the order of a few angstroms. Further, the average grain size in newly developed magnetic recording media is less than the spatial resolution of present MFM systems. Thus, in order for MFM to effectively analyze new magnetic recording media, it is desirable that improvements in the spatial resolution of MFM systems keep pace with the size of these media.